An integrated circuit (IC) device may include a semiconductor die upon which integrated circuitry has been formed, and this die may be mounted on a package substrate or other die carrier. The die may be both electrically and mechanically coupled to the package substrate. By way of example, an array of solder bumps (or other electrical leads) extending from the die may be coupled (e.g., by a reflow process) to a corresponding array of lands (or other electrical leads) on the substrate to form electrical connections between the die and substrate. In addition, an underfill material may be disposed between the die and substrate to secure the die onto the substrate, as well as to protect the electrical connections extending between the die and substrate. The use of an array of solder bumps to provide electrical connections, as described above, is often referred to as Controlled Collapse Chip Connect (or “C4”).
The IC device may further include one or more thermal components coupled with the die, these thermal components functioning to transfer away or otherwise dissipate heat generated by the integrated circuitry during operation. For example, a heat spreader may be thermally coupled with the die, and a heat sink may, in turn, be thermally coupled with the heat spreader. Typically, a first thermal interface is disposed between the die and heat spreader, and a second thermal interface is disposed between the heat spreader and heat sink. The first thermal interface mechanically and thermally couples the die with the heat spreader, with the second thermal interface performing a similar role between the heat spreader and heat sink. The thermal interfaces may comprise any thermally conductive material capable of providing the requisite mechanical attachment, such as a solder material.
Prior to attaching a semiconductor die to a package substrate or die carrier, the die may first be attached to a heat spreader. One type of apparatus used for bonding a die and heat spreader includes a base plate into which two pockets have been machined. The first pocket is deeper and is sized to receive the die, whereas the second pocket is relatively shallower and is sized to receive the heat spreader. The die is typically smaller than the heat spreader, and the periphery of the first pocket lies inside the periphery of the second pocket. During bonding, a die is placed in the first pocket, and a heat spreader is placed over the die and within the second pocket. A solder thermal interface may be disposed between the die and heat spreader, and the assembly (including the bonding apparatus) can then be heated to reflow the solder thermal interface, thereby attaching the heat spreader to the die.
To ensure alignment between the die and heat spreader, as well as to inhibit movement of these components during bonding, the first and second pockets must be machined to precise dimensions, both laterally and depth wise. Further, because precise dimensions need to be maintained, each size of die requires a different fixture having a unique pocket size. Because of the requisite precise dimensions, as well as the inability to use one fixture to hold multiple die sizes, the above-described bonding apparatus and method can be very expensive to implement.